    <div class="col-lg-12">
        <div class="form-group">
            <label>题目名称1:</label>
            <input class="form-control" type="text" name="title" value="">
        </div>
        <div class="form-group">
            <label>题目答案:</label>
            <div class="answer-warp">
                <div class="answer-input" id="answer">
                    <div class="input-group">
                        <span class="input-group-addon">
                            <input type="checkbox" name="result[]" value="0">
                        </span>
                        <span class="input-group-addon">A</span>
                        <input type="text" class="form-control" name="options[]">
                    </div><!-- /input-group -->
                </div>
            </div>
            <div class="margin-top-10" style="margin-top:10px;">

                <a href="javascript:;" id="minus" class="btn btn-primary"><span class="fa fa-minus"></span></a>
                <a href="javascript:;" id="plus" class="btn btn-primary"><span class="fa fa-plus"></span></a>
            </div>

        </div>
    </div>

    <script type="text/javascript">
     var chars = ['A','B','C','D','E'];
     var num = 1;
     var answer = $("#answer");
     var it = answer.children().clone();
     $("#plus").on('click',function(){
         temp = it.clone();
         if(num < chars.length){
             span = temp.find("span");
             item = temp.find("input");
             $(item[0]).val(num);
             $(span[1]).text(chars[num]);
             num++;
             answer.append(temp);

         }else{
             
             return;
         }
     });
     $("#minus").on('click',function(){
         var it = answer.children();
         console.log(it);
         if(it.length == 1 ){
             return;
         }else{
             console.log(1);
             $(it[it.length-1]).remove();
             num--;
         }

     });
    </script>
